1. Field of the Invention
The present invention relates in general to traction apparatus of the type designed for hauling in or out a metal rope by means of a linkage mechanism adapted to impart a to-and-fro movement to two pairs of self clamping jaws, one pair of jaws tightly clamping the rope and moving in the same direction as the rope while the other pair of jaws is released from the rope and moves in the opposite direction.
2. Description of the Prior Art
The U.S. Pat. No. 3,863,893 a modified, lighter construction of an apparatus of this type in which all the component elements of the linkage mechanism are steel stampings, so that manufacturing costs are cut considerably, and wherein the slack end of the rope emerging from one lateral side of the casing is guided by a deflector, so that a very compact and flat apparatus is obtained.
In the construction according to the above-mentioned reference patent the release control member consists of a strap, comprising two rigidly interconnected parallel arms and incorporating at its outer end a flat push knob, this strap bearing with its inner end against a pair of compression springs exerting a pre-clamping pressure on the rope-clamping linkage mechanism.
This strap has a notch formed therein so that, when the strap is pushed against the force of the pre-clamping springs, it can be locked in relation to a latch member, for example the edge of an aperture formed in the casing and slidably engaged by this strap.
In the depressed position, the thus actuated strap compresses the pre-clamping springs associated with the pairs of self-clamping jaws. If an additional pressure is exerted on the strap end while moving it slightly in a lateral direction, the aforesaid notch is released, thus enabling the strap to slide outwardly and to allow the springs to expand, thus eliminating the pressure exerted by the springs on the pairs of self-clamping jaws, so that the rope can be caused to slide freely by hand through the apparatus.